Figure 1.

Schematic representation of the experimental design. Selector cells deficient in responsiveness toward a specific stimulation, here IFN-γ-induced phosphorylation of Stat1, are selected (step 1). After transduction of the retroviral cDNA library into the selector cells (step 2) stimulation and staining of the cells is performed (step 3). Responsive cells are selected by cell sorting (FACS) (step 4). The genomic DNA is isolated serving as a template for the specific amplification of inserted cDNAs that are re-inserted into a retroviral backbone (step 5). Retroviral transfer vectors harboring the selected cDNAs are transduced into naive selector cells and tested for their ability to mediate the reconstitution of the selected phenotype (step 6).